Please help! I'm falling for this guy who has some mental problems. I really don't know what to do :(?

The only way you can get your answers is to confront him and be honest and straight with him, subtly hinting at things through text messages is not going to work. It seems there is something is going on with him but as an outsider I cannot really judge what it is, may be he's confused or insecure and need time to sort things out. Best way is to talk to him, so you can get out of this dilemma.